The primary objective of the study is to compare the efficacy of duloxetine 60 mg by mouth daily with placebo in the prevention of depression associated with mild/moderate traumatic brain injury and to enhance cognitive function. Research exploring the use of selective serotonin reuptake inhibitors in the treatment of post-traumatic depression generally validates this approach (Horsfield et al., 2002). However, the literature suggests that serotonin/norepinephrine reuptake inhibitors such as duloxetine may be more effective in the treatment of depression.